Is JH aware that the magnetic and meteorological observations now being made at Greenwich are to cease at the end of the year? As JH was zealous for these observations he may care to write to S. J. A. Compton (2nd Marquis of Northampton). It escaped his notice that S. D. Poisson and J. B. Biot referred to saturated steam. Return John Robison and Karl Holtzmann to Mansion House when he has read them. Has consulted Thomas Graham about repeating John Southern's experiments.